Referring to FIG. 15 showing the nose and the eye E of a man, the interior of the eye E communicates with a superior canaliculus 2a and an inferior canaliculus 2b by means of small pores opening in a medial part of the eye E on the side of the nose, i.e., a superior lacrimal punctum 1a and an inferior lacrimal punctum 1b. The superior canaliculus 2a and the inferior canaliculus 2b communicate with a lacrimal sac 4 by means of a collective canaliculus 3. The lacrimal sac 4 connects with a nasolacrimal duct 5 extending downward and opening into an inferior nasal meatus 6. In FIG. 15, indicated at 7 is a middle nasal meatus and at 8 is a middle turbinate bone.
A lacrimal silicone tube is a nasolacrimal stent for the plastic surgery of the lacrimal passage including a lacrimal punctum, a canaliculus, a lacrimal sac and a nasolacrimal duct. The lacrimal silicone tube is applied often to lacrimal passage plastic surgery and canaliculus plastic surgery as a stent, and as an insert to the prevention of dacryostenosis as a complication of radiotherapy.
FIGS. 16 and 17 are views of assistance in explaining a method of using a silicone tube device provided with such a silicone tube. As shown in FIG. 16, the silicone tube device has a flexible silicone tube 9, and metal probes 10 having the shape of a rod and connected to the opposite ends of the silicone tube 9, respectively. Each probe 10 has a distal end formed in a bulge 11. As shown in FIG. 17, when using the silicone tube device, the probes 10 are inserted through the superior lacrimal punctum 1a and the inferior lacrimal punctum 1b, and the lacrimal sac 4 into the nasolacrimal duct 5. First the bulges 11 formed at the distal ends of the probes 10 are inserted through the superior lacrimal punctum 1a and the inferior lacrimal punctum 1b into the superior canaliculus 2a and the inferior canaliculus 2b, respectively. The probes 10 are inserted deeper into the nasal cavity and a special hook 12 is engaged with each bulge 11 to pull out the probe 10 from the nasal duct as shown in FIG. 17. Thus, the silicone tube 9 can be extended through the lacrimal puncta 1a and 1b and the inferior nasal meatus by the guiding action of the probes 10. After such silicon tube inserting work has been completed, the probes 10 are disconnected from the silicone tube 9 when necessary, and opposite end parts of the silicone tube 9 are tied in a knot 13 so that the silicone tube 9 may not come off as shown in FIG. 18. Thus, the silicone tube 9 is left in the body as a stent to keep the lacrimal passage unobstructed.
Particularly, the lacrimal sac 4 and the nasolacrimal duct are dark. Therefore the silicon tube device must be operated by feel in the nasal duct when inserting the silicon tube device into the lacrimal passage, and hence it often occurs that the silicon tube device deviates from a correct passage, a false passage is formed in tissues, and nasal mucous membranes are damaged causing massive hemorrhage. Thus the work for the insertion of the silicon tube device in the lacrimal passage is very difficult. To avoid such troubles and to overcome such difficulties, there have been proposed a silicone tube device inserting method that uses an endoscope for the observation of the lacrimal passage, and a silicone tube device inserting method that uses a surgical lamp for illumination. However, the former method requires difficult work to use fingers for surgical operations, observing pictures taken by an endoscope and displayed on a monitor. The use of a surgical lamp is not perfectly effective because it is difficult to illuminate the interior of the nasal duct directly with the surgical lamp.
The present invention has been made to solve those problems and it is therefore an object of the present invention to provide a nasolacrimal stent which can be surely and readily pulled through the nasal duct and pulled out of the nasal duct for intubation without damaging nasal mucous membranes and without causing massive hemorrhage, and to provide a nasolacrimal stent device.